Light reflecting sign or marker



April 4, 1944. J. WEBER 2,345,644

LIGHT REFLECTING SIGN OR MARKER Filed 'April 1, 1942 Patented Apr. 4, 1944 UNITED STATES FATENT OFFICE Institute, Washington, D.

rated association 0., an unincorpo- Application April l, 1942, Serial No. 437,221

12 Claims.

Increasing use is being made of white Portland cement for marking curbs, center lines and lanedividing lines for paved roads, as well as warning signals on posts alongside of roads. The effectiveness of this expedient is limited by various factors. For example, when it rains at night, the cement has the appearance of being almost black under the illumination of automobile headlights; because such light as strikes it is reflected forwardly, away from the driver, instead of back to the source. In the case of curbs, the efficiency of the white cement has been improved by giving to the surface a saw toothed arrangement which reflects light back to the source instead of diffusing it in all directions as does a smooth surface. This latter expedient is not suitable for areas over which traffic must pass.

I have discovered that white cement may be rendered highly efficient for road and street marking, whether in curbs, pavements or on sign posts, regardless of the time of day or the weather conditions, and regardless of how long'the markings are in use. This I accomplish by partially embedding large spherical glass balls in the cement; the cement forming a reflecting surface behind each ball, adequately shielded against damage through contact with external objects or through being covered with dirt or other foreign substance that would darken the same. The balls must be large in order that strong light beams may be reflected back through the same, and in order that they shall be strongly held in the cement. Not only must the balls be large, but they must be spaced far apart. If the balls are close to each other, the stresses to which the cement body is subjected under wide variations in temperature causes the weak sections between the balls to fail and the balls to become loose.

Where the balls are placed in the roadway they are preferably about an inch in diameter, although they may be somewhat smaller. When they are placed in the face of a curb, smaller balls may be employed.

The smallest balls are suitable for areas which the light strikes head on as, for example, a sign on a post or panel beside a road and having its face arranged at a right or other angle to the path of travel along the road. In the case of a sign post, half inch balls are satisfactory; but in the case of a flat panel arranged approximately at right angles to the beam of light striking it, the balls may be as small as a quarter of an inch placed closer together than is desirable in the case of large balls. I prefer to employ balls of maximum rather than of minimum diameters since the cross-sectional area of the reflected beam varies according to the square of the diameter and, the larger that the balls are within limits, the more powerful will be the individual reflected beams. 1

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description. taken in connection with the accompanying drawing, where- Figure 1 is a section through a paved road on a vertical plane parallel with a curb embodying the present invention, showing only a fragment of each; Fig. 2 is a section on line 22 of Fig. 1; Fig. 3 is a view similar to Fig. 2, showing a slight modification; Fig. 4 is a top plan view of a frag.- ment of a paved road containing a longitudinal division strip constructed and arranged in ac cordance with the present invention; Fig, 5 is a view, similar to Fig. 4, but on a larger scale, showing a smaller fragment; Fig. 6 is a section on line fi-6 of 5; Fig. 7 is an elevational view of a post standing beside a road and embodying the present invention; Fig. 8 is a section on line 8-8 of Fig. '7; and Fig. 9 is a section on a much larger scale, showing a fragment of the ball-car rying panels or bodies disclosed in any one of the preceding figures, the section being taken through the center of one of the balls which, however, appears in elevation.

' In the arrangement shown in Figs. 1 and 2, l is any usual or suitable curb along the side of the paved portion 2 of a road. Set into the inner side of the curb is a panel 3, preferably precast, formed of white Portland cement and any suitable aggregate. Embedded in the exposed face of this panel are glass balls 4 which usually are transparent although, for some purposes, they may be colored so as still to be permeable by light rays. Colored balls are used only when it is desired to have colored light beams traveling from the curb to the observer. I have found that very good results are obtained by employing balls that are quite large and which are spaced far apart. While the size of the balls may vary,I believe an optimum diameter to be about three quarters of an inch. With balls of that size they may be placed in a plurality of horizontal rows, with the balls in one row staggered relatively to the balls in the adjacent rows. In the arrangement shown, there are three such rows, the center lines of which narrowest spaces between the balls.

may be placed about an inch and a half apart, and the balls in each row being four or five inches apart. In other words, the balls cover only a small fraction of the area in which they are found. Therefore, in the daytime, the affect will be very much the same as though the curb contained a plain white strip. At night, however, the balls provide the illumination which is at best only inadequately supplied by a plain or smooth strip. The spacings between balls are so great that the cement does not weaken and deteriorate in particular small areas, as is the case where the balls are so close together that only narrow bridging pieces of concrete fill the Accordingly, there is no tendency for the cement to crack and break up around each ball; and, by embedding a little more than one half of each ball in the concrete, it is So firmly held that it can be removed only by cutting away theconcrete with suitable tools.

Since the rim of a vehicle wheel, striking the balls at high speed, might result in damage thereto, the ball-carrying panel may have a recessed face in the area where the balls are located, so as to place the balls behind the plane of the inner face of the curb. Such an arrangement is shown in Fig. 3 in which the insert 5 is recessed, as indicated at 6, throughout the entire area in which the balls are located; the depth of the recesses being approximately equal to the distance which the balls project from the surface in which they are embedded. With this arrangement a wheel rim running along the curb and rubbing against same engages the curb face above and below the zone in which the balls are located, and is held away from the balls.

In Figs. 4, 5 and 6 there is illustrated a traflic dividing means in the roadway itself. This means may be for the purpose of separating traflic that goes in opposite directions, or for the purpose of marking lanes for trafiic going in the same direction. In this construction, the pavement is provided with a wide, deep groove or slot 1 extending longitudinally of the same in the desired location. Within this groove or slot is inserted a ball-carrying strip, preferably formed of precast slabs or panels placed end to end; the panels, as in the case of those in the curb, being composed of white Portland cement and any suitable aggregate. The particular construction illustrated is one suitable for use in positions over which vehicles are permitted to run and therefore the top of the slabs or panels is approximately flush with the road surface, although they are shown as having slightly convex upper faces 9 to permit water to run 011. Obviously, if it is desired to prevent vehicles from passing from one side of the division line to the other, the slabs or panels must be caused to project above the roadway, in the usual manner, to prevent vehicles from moving across the same. Somewhat larger balls can be used in the roadway than are needed along the curbs, and I believe that the most suitable size is balls having a diameter of about one inch. Because the balls are in an approximately horizontal plane, below the observer, they may be placed farther apart than those in the curb. In the arrangement shown, the balls in each of the three rows are placed more than a foot apart, and the spacing may be several feet.

In Figs. '7 and 8 there is illustrated a round sign post I! having set into the side of the same a panel 12 composed of white Portland cement and aggregate; this panel extending about one quarter of the way around the post and being of any desired height. Projecting from the face of this panel are balls l3 partially embedded in the concrete. As in the case of the other panels or strips the balls are shown as being arranged in three staggered rows which, in this instance, are vertical. However, any other desired arrangement of the balls, as long as they are properly spaced, may be used here as well as in the curb or roadway. The balls I3 may be as large as those used in the curb or roadway, or they may be even smaller, say one half inch in diameter. I have found that because the light beams are thrown against at least some portions of the panel l2, approximately at right angles to the surface thereof, balls not much more than one fourth of an inch in diameter are effective.

In Fig. 9 a ball I4 is shown in its setting IE on a sufliciently large scale to illustrate clearly the extent to which the ball is embedded in the concrete. Assuming the ball to be one inch in diameter, the center may lie inward from the face of the concrete member IS a distance of about one eighth of an inch, thus allowing the ball to project about three eighths of an inch beyond the concrete. If it be desired that the areas between the balls in the face of the member l5 be colored instead of white, the aggregate that is mixed with the cement may be of the desired color. Then, upon washing out the cement at the surface, either with acid, after the cement has dried, or by brushing while the cement is still wet, the balls serve as signals at night and the exposed aggregate.

It will be understood that while the slabs or panels are preferably precast to simplify manufacture and insure greater uniformity in the product, the white cement concrete may be poured and the balls be inserted therein at the place of use.

It should also be noted that, although I have spoken of the slabs, panels or strip as being white, obviously if whiteness is desired only to secure reflection through the balls, only such cement as forms the reflector surfaces behind the balls need be white; so that in that case a layer of White cement may be applied to that portion of each ball that is to be embedded in the support, and a different kind of cement may then be employed in the body of the slab, panel or strip. When I refer to a white slab, panel or strip I mean to include any concrete structure in which the balls are backed with white cement for refleeting light.

While I have illustrated and described in detail several embodiments of my invention based on the particular use to which it is to be put. I do not desire to be limited to such details except so far as they may be essential to the practice of the basic concept of large transparent or translucent glass balls partially embedded in conorete in such a manner as to remain firmly held indefinitely and be backed by white reflecting surfaces; the scope of the invention being set forth in the definitions of the invention constituting the appended claims.

I claim:

1. A light-reflecting device consisting of a body member of white Portland cement and large balls of glass permeable by light embedded in the cement, in widely spaced relation to each other, to a depth somewhat greater than one half of their respective diameters.

2. A light-reflecting device consisting of a body member of white Portland cement and balls of glass permeable by light and at least one half inch in diameter embedded in the cement, in spaced relation to each other, to a depth some what greater than one half of their respective diameters.

3. A light-reflecting device consisting of a body member of white Portland cement and balls of transparent glass at least one half inch in diameter embedded in the cement, in spaced relation to each other, to a depth somewhat greater than one half of their respective diameters.

4. A light-reflecting device consisting of a body member of white Portland cement and balls of colored glass permeable by light and at least one half inch in diameter embedded in the cement, in spaced relation to each other, to a depth somewhat greater than one half of their respective diameters.

5. A light-reflecting device consisting of a body member of white Portland cement and glass balls permeable by light and about an inch in diameter embedded in the cement, in spaced relation to each other, to a depth somewhat greater than one half of their respective diameters.

6. A light-reflecting indicator in a pavement consisting of a thick panel of white 1 )rtland cement and a suitable aggregate the top of which is about flush with the surface of the pavement, and large glass balls permeable by light rays embedded in the cement to a depth somewhat greater than one half of their diameters, the minimum distance between balls being at least as great as their diameters.

I. A light-reflecting indicator in a pavement consisting of a thick panel of white cement and a suitable aggregate the top of which is about flush with the surface of the pavement, and glass balls permeable by light rays and having a diameter of about one inch embedded in the cement to a depth somewhat greater than one half of said diameter, the minimum spacings between balls being at least as great as their diameters.

8. A light-reflecting indicator in a pavement consisting of a series of thick pre-cast panels of white cement arranged end to end in and having their upper faces about flush with the surface of the pavement, and glass balls permeable by light rays and having a diameter of about one inch embedded in each of said panels to a depth somewhat greater than one half of said diameter.

9. A light-reflecting device consisting of a self supporting member of white Portland cement and a suitable aggregate, together with large balls of glass permeable by light embedded in the cement to a depth somewhat greater than one half of their respective diameters, the balls being spaced from each other farther than the diameters thereof.

10. A light-reflecting device consisting of a thick, self supporting panel of white Portland cement and balls of glass permeable by light and at least one half inch in diameter embedded in the cement, in spaced relation to each other, to a depth somewhat greater than one half of their respective diameters.

11. A light-reflecting sign comprising a post provided with a section of white cement and a suitable aggregate and large glass balls permeable by light rays embedded in widely spaced relation to each other in the cement to a depth somewhat greater than one half of said diameter over an area extending about one fourth of the way around the post and of a considerable height.

12. A light-reflecting device consisting of a body member of Portland cement and large balls of glass permeable by light embedded in the ce ment, in widely spaced relation to each other, to a depth somewhat greater than one half of their respective diameters, the cement in contact with the balls being white.

JACOB WEBER. 

